The advantages of digitized video and music are numerous, but one significant drawback is that being digitized, the content is relatively easy to copy perfectly, without authorization of the copyright owner. Copies can be made of digital audio and video content that is provided to in-home users on media such as digital versatile disks (DVDs). Indeed, widespread copying by pirates costs content owners billions of dollars per year. Thus, the present invention understands that it is desirable to limit the unauthorized copying of digital audio and video. Consequently, many copy guard schemes have been introduced to prevent unauthorized copying of a vended CD or DVD.
The problem, however, is complicated by the desire of buyers of digitized content to make copies for personal uses. For example, a buyer of a DVD movie might have a home entertainment network that might include several DVD players, personal video recorders (PVRs), and other computing devices such as personal computers (PCs) and personal digital assistants (PDAs) on which the buyer might want to play, at various times, the purchased content. Under these circumstances, the buyer would prefer to access and copy the content over digital channels, rather than transport the purchased DVD to each device. Moreover, some of the network devices might not be configured for receiving a DVD or other media format on which the content was purchased. Assuming the appropriate controls can be established, content providers in general do not object to such copying, because it is merely a convenience for a buyer who has already purchased the content and desires to use it solely for his or her own personal enjoyment.
But as intimated above, if such functionality is permitted without constraints, unscrupulous purchasers could open their home networks to unauthorized users or make pirate copies of the content that they could then sell or give away, depriving copyright owners of compensation. The present invention has been provided with the above critical observations in mind.